Mandrel stripper for mat winding machine



March 31, 1964 A. Mc'PHERsoN x-:TAL 3,127,024

MANDREL STRIPPER FORMAT WINDING MACHINE Filed Nov. ze, 1957 9 Sheets-Sheet l March 31, 1964 A. L.. MCPHERSON ETAL MANDREL STRIPPER FOR MAT WINDING MACHINE Filed Nov. 26, 1957 9 Sheets-Sheet 2 ATTORNEY March 3l, 1964 A. L. McPHERsoN ETAL 3,127,024

MANDREL STRIPPER FOR MAT wINDING MACHINE Filed Nov. 2e, 1957 9 Sheets-Sheet 3 ATTORNEY March 3l, 1964 A. L. MCPHERSON ETAL MANDREI.. STRIPPER FOR MAT WINDING MACHINE Filed Nov. 26, 1957 9 Sheets-Sheet 4 F15 ii INVENTORS Bm; Ey

ATTORNEY March 31, 1964 A. L. MGPHERSON ETAI. 3,127,024

MANDREL sTRiPPER FOR MAT wINDING MACHINE Filed Nov. 2e, 1957 9 Sheets-Sheet 5 March 3l, 1964 A. L.. MCPHERSON ETAL 3,127,024

MANDREL .STRIPPER Foa MAT wmnmc MACHINE:

Filed Nov. 26, 1957 9 Sheets-Sheet 6 March 31, 1964 A. MoPHERsoN ETAL 3,127,024

MANDREL STRIPPER FOR MAT WINDING MACHINE Filed Nov. 2e, 1957 4 sheets-sheet '1 INVENTORS msm/w52 MS Dx/5250A! /MQOLD 6. BAILEY March 31, 1964 A. MoPHERsoN ETAL 3,127,024

MANDREL STRIPPER FOR MAT WINDING MACHINE I Filed Nov. 26, 1957 9 Sheets-Sheet 8 56 A ORNEY March 3'1, 1964 A. McPHERsoN ETAL 3,127,024

MANDREL STRIPPER FOR MAT wINmNG MACHINE United States Patent O 3,127,024 MANDREL STRIPPER FOR MAT WINDING MACHINE Alexander L. McPherson, Prairie Village, Kans., and Harold G. Bailey, Akron, and Arthur D. Stevens, Cuyahoga Falls, Ohio, assignors to Gustin-Bacon Manufacturing Company, Kansas City, Mo., a corporation of Missouri Filed Nov. 26, 1957, Ser. No. 698,971 Claims. (Cl. 214-1) Our invention relates to a mandrel stripper for a mat winding machine and more particularly to apparatus for automatically removing a mandrel carrying a cured mat forming a tube of insulation from an oven, stripping the mandrel from the tube of insulation and trimming the ends of the tube.

The eopending application of Frederick N. Stephens et al., Serial No. 491,312, filed March 1, 1955, for a'Rotary Oven, now Patent No. 2,979,765, issued April 18, 1961, discloses an oven for automatically receiving mandrels wrapped with lengths of a mat or bat of fibrous material impregnated with an uncured resin from a winding machine such as is disclosed in Patent No. 2,742,240 issued April 17, 1956, to Joseph F. Stephens et al. for a Mat Winding Machine. The oven cures the resin and automatically discharges the mandrels carrying the tubes of insulating material formed by the mat windings after the impregnating resin is cured. When the operations performed by the oven disclosed in the copending application are complete, it is necessary that the mandrels be stripped from the tubes of insulation and be returned to the mat winding machine which supplies the oven. Further, it is necessary that the ends of the tubes of insulation be trimmed to remove excess material from the lengths of insulation. It will be appreciated the operations of removing the wrapped mandrels from the oven, stripping the mandrels from the tubes of insulation and trimming the tube ends, if performed manually, are time consuming and expensive. Manual performance of these operations does not permit advantage to be taken of the potential production capacity of the mat winding machine and rotary oven referred to hereinabove.

We have invented automatic means for removing wrapped mandrels from the curing oven and for conveying them to a mandrel stripper. We have invented a mandrel stripper which automatically receives wrapped mandrels carrying tubes of insulation and which automatically strips the mandrels from the tubes of insulation. Our machine includes means for trimming the ends of the tubes of insulation after the stripping operation has been performed. We provide means for automatically removing stripped mandrels from the stripper and for feeding the removed mandrels to a conveyor which returns the mandrels to the mat winding machine. Our automatic mandrel remover and stripper permits us to take advantage of the high rate of production possible with automatic wrapping and curing machines such as are referred to hereinabove. Our machine permits us to form a greater number of finished tubes of insulating material in a given length of time.

One object of our invention is to provide apparatus for automatically stripping mandrels from tubes of insulating material formed on the mandrels.

Another object of our invention is to provide improved apparatus for'removing mandrels from a curing oven or the like.

Still another object of our invention is to provide a mandrel stripper for mat winding machines having means for automatically removing stripped mandrels from the mandrel stripper to a return conveyor.

Yet another object of our invention is to provide a mandrel stripper for mat winding machines which per- ICC mits us to take advantage of the potential production capacity of automatic winding machines and curing ovens.

A still further object of our invention is to provide a mandrel stripper for mat winding machines which provides a continuous process for the formation of tubes of insulating material.

Other and further objects of our invention will appear from the following description.

In general our invention contemplates the provision of improved means for removing a wrapped mandrel from the open mold of an automatic curing oven and for feeding the wrapped mandrel to our mandrel stripper. Our mandrel stripper has pairs of arms mounted at circumferentially spaced locations around a shaft adapted to be stepped to a mandrel stripping station and to a station at which a stripped tube of insulation is delivered to a discharge conveyor. As the shaft is stepped from one station to the other, grippers carried by one pair of arms are actuated to grasp a tube of insulation carried by a mandrel on the conveyor leading from the curing oven and to move this mandrel to the stripping station. At the same time, the other pair of arms moves from the stripping to the delivery station and its grippers, which had been closed, open to deliver a stripped tube of insulation to the discharge conveyor. In the course of movement of a stripped tube of insulation from the stripping to the delivery station the ends of the tube are trimmed by the cutters of our apparatus. Between steps of the machine shaft a chuck carried by a movable piston rod moves to grip the end of a mandrel shaft at the stripping station. As the chuck is withdrawn, the grippers retain the tube of insulation while the chuck draws the mandrel out of the tube. When the mandrel has been withdrawn, the chuck is released and automatic unloading arms pick up the mandrel to feed it to a return conveyor leading to the mat winding machine with which our mandrel stripper is used. In order to increase the capacity of our machine we disposed a pair of mandrel strippers in side by side relationship and operate them out of phase to permit two mandrels to be stripped at the same time. We accomplish this last result without wasting floor space.

In the accompanying drawings which form part of the instant specification and which are to be read in conjunction therewith and in which like reference numerals are used to indicate like parts in the various views:

FIGURE 1 is a front elevation of our mandrel stripper for mat winding machines showing two stripping units.

FIGURE 2 is a top plan view of the form of our mandrel stripper for mat Winding machines taken along the line 2-2 of FIGURE l.

FIGURE 3 is an end elevation of our mandrel stripper for mat winding machines drawn on an enlarged scale with some parts removed taken along the line 3 3 of FIGURE l.

FIGURE 4 is a fragmentary sectional view of our mandrel stripper for mat winding machines taken along the line 4 4 of FIGURE l and drawn on a greatly enlarged scale.

FIGURE 5 is a diagrammatic view of the gripper actuating cams of the units of our mandrel stripper for mat winding machines showing the relative angular disposition of the cam tracks of the two units.

FIGURE 6 is a fragmentary sectional view of the mandrel unloader of our mandrel stripper for mat winding machines taken along the line 6-6 of FIGURE 2 and drawn on a greatly enlarged scale.

FIGURE 7 is a fragmentary front elevation of one unit of our mandrel stripper for mat winding machines.

FIGURE 8 is a fragmentary top plan view of one unit of our mandrel stripper for mat Winding machines.

FIGURE 9 is a fragmentary side elevation of our oven il) unloader used with our mandrel stripper for mat winding machines.

FIGURE is a fragmentary sectional View of the oven unloader of our mandrel stripper for mat winding machines showing the unloader arms in the position occupied when a wrapped mandrel is being deposited on the conveyor and taken along the line 10-10 of FIGURE 9.

FIGURE 11 is a schematic view of one form of control circuit which may be used with our automatic stripper for mat winding machines.

More particularly referring now to FIGURES 9 and 10 of the drawings, as has been explained hereinabove, our mandrel stripper may be used with an automatic curing oven such, for example, as that which is disclosed in the said copending application, Serial No. 491,312. This oven includes a plenum chamber, indicated generally by the reference character 10, with which a plurality of radially extending conduits 12 communicate. The conduits 12 communicate with the interiors of the oven molds carried by casting sections 14, 16 and 18, which sections are hinged together in the manner disclosed in the copending application. As is explained in detail in the copending application the mold sections 16 and 18 are adapted to be moved to an open position by a linkage including a spring 20 connected to section 18, an eye member 22 connected to the spring, a link 24 and a crank 26, carried by a shaft 28 operated by a cam track (not shown) to open the mold after the resin impregnating a tube such as tube 30 carried by a mandrel 32 having shaft ends 34, has been cured. By way of example in FIGURE 9 we have shown one open mold and one closed mold.

Our apparatus for automatically removing a wrapped mandrel, such as mandrel 32, from an open mold includes a pair of arms 34 and 36 carried by a shaft 38 rotatably supported in bearings, one bearing 40 of which is shown in FIGURE 9 mounted on a support 42 located adjacent the oven 10. Any convenient means such as a key 44 or the like secures a crank 46 on the end of shaft 38 outboard of one of the bearings 40 for rotation with the shaft. A pin 48 pivotally connects the end of crank 46 remote from shaft 38 to a piston rod 50 associated with a cylinder 52. A pin 54 pivotally connects the cylinder 52 to a bracket S6 on support 42. Fluid under pressure admitted, in a manner to be described hereinafter, to cylinder 52 on one side of the piston associated with rod 50 actuates crank 46 to move arms 34 and 36 up toward the open mold. When the ow of fluid to cylinder 52 is reversed in a manner to be described hereinafter, crank 46 drives shaft 38 in the other direction to move the arms 34 and 36 away from the open mold. Respective slots 58 formed in the ends of arms 34 and 36 carry pins 60 which pivotally support latches 62. Springs 64 each have one end disposed in a recess 66 formed in a plate 68 secured to the end of the associated arm. I dispose the other end of each spring in a recess 70 formed in one end of the associated latch 62 normally to urge the latch to rotate its upper end inboard as viewed in FIG- URE 10. As the arms 34 and 35 rotate in a clockwise direction, as viewed in FIGURE 9 under the influence of fluid admitted to cylinder 52, cam surfaces 72 formed on the ends of the latches ride over the mandrel shaft ends 34 to rotate the latches 62 against the action of springs 64. When the arms 34 and 46 have moved the latches over the mandrel shaft ends so that the surfaces 72 no longer are in engagement with the ends 34, the springs 64 position the latches over the mandrel shaft ends. The direction of ow of fluid to cylinder 52 is reversed at this time and arms 34 and 36 move in a counterclockwise direction, as viewed in FIGURE 9. In the course of this movement of the arms, latches 62 pull the wrapped mandrel out of the empty mold and onto notches 74 formed in the tops of plates 68. It will be seen that as the arms move in this manner, the Wrapped mandrel is carried downwardly, as viewed in FIGURE 9, toward a conveyor, indicated generally by the reference character 76, formed by a pair of spaced pitch chains 78 and 80. A pair of sprocket wheels, one wheel 82 of which is shown in FIGURE 9, are driven in a manner to be described hereinafter to move the chains 78 and 80 in the direction of the arrow A in FIGURE 9. When the wrapped mandrel has been moved down between chains '78 and 80, its ends 34 are positioned in spaced V blocks 84 carried by the chains.

A pair of supports 86 and 88 disposed outboard of chains 78 and 80 carry cam blocks 90 having cam surfaces 92 adapted to be engaged by the lower ends of latches 62, as viewed in FIGURE 10, as arms 34 move downwardly into the respective spaces between chain 78 and support 86 and between chain 80 and support 88. When the lower ends of the latches 62 engage surfaces 92, their upper ends move outwardly of the shaft ends 34, as viewed in FIGURE 10, to release the mandrel shaft ends and permit them to come to rest in V blocks 84 to be carried away from the oven by chains 78 and 80. Guides 94 and 96 carried by a supporting platform 98 support and guide chains 78 and 80 in the course of their movement from the oven to the mandrel stripper to be described hereinafter.

Referring now to FIGURES 1 to 3, the chains 78 and 88 carry the mandrels from the oven 10 to our mandrel stripper, the framework of which is indicated generally by the reference character 100. Chain 78 can be seen in FIGURE 3. As is indicated in the figure, a motor 102 drives a shaft 104 carrying a sprocket wheel 106 and for rotation with the shaft to drive a chain 10S which drives a sprocket wheel fixed on a shaft 112 rotatably supported in a bearing 114 carried by a bracket 116 on the frame 100. Motor 102 provides a drive for the chains 78 and 80.

As has been explained hereinabove, we employ two of our mandrel stripper units, indicated generally respectively by the reference characters 118 and 120 in FIG- URES 1 and 2. By using two of the units and operating them out of phase, we are able to increase the production of the installation at which our strippers are located. When we use two units 118 and 120, it will be clear that two conveyors, each including a pair of chains 78 and 80, are employed to convey wrapped mandrels from two respective ovens 10. Since the units 118 and 120 are substantially identical in detail, for purposes of simplicity only one of the units will be described in detail.

Referring to figures 1 to 4 and 7, respective bearings 122 and 124 carried by supports 126 and 128 of the machine frame rotatably support the main drive shaft of our mandrel stripper. A respective clutch 132 and brake 134 are adapted to be operated in a manner to be described to couple shaft 130 to a shaft 136 driven by any suitable prime mover known to the art. A key 138 fixes a hub 140 carrying a pair of oppositely extending arms 142 and 144 on shaft 130 for rotation with the shaft. Another key fixes the hub of another pair of arms on shaft 130 at a location spaced from the location at which key 138 secures hub 140 to shaft 130. Each unit 118 and 120 has a set of spaced pairs of arms 142 and 144 carried by shaft 130. Since all pairs of arms and their associated structures are similar, only one pair of arms will be described in detail. We secure stationary grippers 146 and 148 to the ends of the respective arms 142 and 144. Pins 150 and 152 carried by the respective arms 142 and 144 pivotally support respective movable grippers V154 and 156. The grippers of each pair of grippers 154 and 146 and 156 and 148 are so shaped that they may be moved toward each other to grasp a tube of insulation wrapped around a mandrel. As has been explained hereinabove, one arm 142 supports the grippers 146 and 154 at one location on shaft 130, while a second arm 142 axially spaced from the first arm 142 supports another pair of grippers 146 and 154. It is to be understood that the second arm 142 of a unit extends in the same direction from the shaft 130 as does the rst arm 142. The hub 140 associated with the second arm 142 also carries a second arm 144 having a second pair of grippers 148 and 156.

We provide means for actuating the pairs of grippers 146 and 154 and the pairs of grippers 148 and 156 to close to grasp a tube of insulation carried by a wrapped mandrel and to open to release a tube of insulation from which the mandrel .has been stripped at predetermined stations in the course of a revolution of shaft 130. A link 158 pivotally carried by a pin 160 on the movable gripper 154 is pivotally connected by a pin 162 to the end of a crank 164. A key 166 ixes crank 164 on a pivot shaft 168 rotatably supported in an extension 170 formed on hub 140. A second crank 172 supported by shaft 168 for rotation with the shaft carries a cam follower roller 174 disposed in the track 176 of a stationary cam 178. Any convenient means such as brackets 180 may be employed to support the stationary cams 178 on the frame support 126. While we have described only one of the stationary cams 178, it is to be understood that one stationary cam 178 is associated with each of the gripper arm assemblies including the arms 142 and 144.

A pin 182 pivotally connects one end of a link 184 to the movable gripper 156. A pin 186 connects the end of link 184 remote from pin 182 to the end of a crank 188 fixed on a shaft 190 for rotation with the shaft by means of a key 192. Any convenient means known to the art rotatably supports shaft 190 in an extension 194 on hub 140. A second crank 196 supported by shaft 190 for rotation with the shaft carries a cam follower roller 198 disposed in the track 176 of the stationary cani 178.

In the position of grippers 146 and 154 shown in FIGURE 4, the linkage including cranks 164 and 172 and link 158 actuates the movable gripper 154 to close the pair of grippers 154 and 146 to the position at which they may grasp a tube of insulation carried by a wrapped mandrel. As shaft 130 rotates in a counterclockwise direction, as viewed in FIGURE 4, track 176 actuates crank 172 through the medium of follower 174 to rotate the crank in a clockwise direction. This rotation of crank 172 rotates crank 164 in a clockwise direction to operate link 158 to move the movable gripper 154 to the open position which is shown as being occupied by movable gripper 156 in FIGURE 4. Also in the course of this movement the actuating linkage for gripper 156 operates the gripper to move it to a position at which it may grasp a tube of insulation carried by a wrapped mandrel. v

As can be seen by reference to FIGURE 3 in the posltion of the pairs of grippers 146 and 154 and 156 and 148, the pairs of grippers 148 and 156 are in a position to receive a wrapped mandrel 32 as shaft 130 steps in a clockwise direction, as viewed in the ligure. In this position of the grippers a Wrapped mandrel 32 carried by the conveyor chains 78 and `80 is in a position to be picked up by the stationary grippers 148. As shaft 130 steps through a half revolution in the clockwise direction, as viewed in FIGURE 3, the stationary grippers 148 move up between chains 78 and 80 to pick the wrapped mandrel 32 off the conveyor. As rotation of shaft 130 continues, the movable grippers 156 are actuated to close over the tube 301 of insulation carried by the mandrel 32 firmly to hold the tube in a manner which permits the mandrel 32 to be stripped from the tube. At the same time, the pairs of grippers 146 and .154 carrying a tube 30 of insulation from which the mandrel has been stripped in a manner to be described open to permit va tube 30 to fall free of the grippers onto a delivery conveyor, indicated generally by the reference character 200, which carries the tube away from the machine. A guide 202 supported from the machine frame in any convenient manner may be employed to ensure that the tube falls onto conveyor 200. From the description advanced hereinabove, it will be clear two pairs of grippers 146 and 6 `154- and 148 and 156 are offset from the other two pairs of grippers 146 and 154 and l1'48 and 156. This will be clear from the arrangement pointed out hereinabove which includes two conveyors which are operated out of synchronism with each other.

Referring again to FIGURES 1 and 2, our stripper includes respective piston and cylinder assemblies, indicated generally by the reference characters 204 and 206 which form part of the stripping apparatus of our mandrel stripper. The arrangement of our stripper is such that the assembly 204 is associated with the unit and the assembly 206 is associated -with the unit V118.

Referring now to FIGUR-ES 7 and 8, the assembly 204 includes a cylinder 208 and a piston rod 210 to which We secure a pneumatic chuck 212 adapted to grasp the 4end of a mandrel carried by the pairs of grippers 146 and 154 of the unit 120. We secure a pair of Slider bars 214 and 216 to the upper end of a yoke 218 carried by chuck 212. Suitable guides 220 and 222 slidably support rods 214 and 216 on the machine frame to provide additional support for the chuck 212 when piston rod 210 is extended in a manner to be described. As will be explained in detail hereinafter, after shaft completes a stepping operation to position the pairs of grippers v146 and 154 of each unit at a location at which the wrapped mandrel carried by the grippers is in a position to be acted upon by the chuck 212 of the mandrel withdrawing unit 204 or 206 associated with the unit 120 or y118, fluid under pressure is supplied to the cylinder to move the piston'rod 210 out of the cylinder to move the chuck 212 toward the unit with which it is associated. As has been explained hereinabove, the assembly 204 is associated with unit v120. We so arrange our machine in order to obviate the necessity of having to draw the mandrels outboard of the -units which would require the piston and cylinder units 204 and 206 to be positioned a distance away from the machine, thus requiring more oor space for the installation. As fluid under pressure is supplied to cylinder '208 to drive piston rod 210 out of the cylinder chuck 212 moves to the right as viewed in FIGURE 7 across the unit 118. In order to prevent interference of the parts of the unit 118 with this movement of chuck 212, we operate the conveying units 118 and 120l out of phase with each other. That is, the stripping station of the unit 118 is spaced circumferentially about shaft 130 from that of the unit 120. We accomplish this by relatively angularly disposing the cam tracks 178 of the unit 118 with respect to the cam tracks `of unit 120.

Referring -now .to FIGURE 5, we have shown the track 178 formed in one of the stationary cam plates 176 of the unit 118. We have indicated the positions of the followers 174 and 198 and have shown a mandrel shaft end 34 in the position in which it is held by the grippers 146 and 154 of unit 118 to permit it to -be grasped by the chuck 212 of the assembly 206. In broken lines we -have shown the track 224 of a stationary cam plate of the unit 120. The positions of the followers 198 and 174 riding in this cam track are indicated in broken lines. We have also indicated in broken lines the position of a mandrel end 34 of a mandrel held in stripping position by the grippers 1-46 and 154 of the unit 120. From FIGURE 5 it will be apparent that the axes of the mandrel ends positioned for stripping by the respective units 118 and 120 are spaced circumferentially with respect to shaft 130 by an angle of 45 degrees. This operation of the units 118 and 120 out of phase permits the chuck of assembly 206 to travel across the unit 120 to grasp a mandrel end positioned by unit 118 for stripping and permits the chuck of unit 204 to travel across unit 118 to permit it to grasp the end ofl a mandrel positioned by unit 120. Thus, unit 204 disposed adjacent the unit 218 is operatively associated with unit 120 while unit 206 disposed adjacent unit 120 is operatively associated with unit 118. We mount the respective assemblies 204 and 206 on the machine frame, as shown in =FIGURE 2, in positions at which they are axially aligned with mandrels positioned by the respective units 120 and 118. In this manner we simultaneously strip mandrels lfrom two tubes of insulation positioned by the respective units.

Referring again to FIGURES 1 to 3, a plurality of drive motors 226 carried by the machine frame drive respective belts 228, each of which drives a shaft 238 rotatably supported in bearings 232 in the machine frame. We mount a respective cutting blade 234 on each of the shafts 230 for rotation with the shaft. Motors 226 are energized from any convenient source of electrical energy to drive the saws or cutters 234 continuously. The saws 234 are positioned so that as a tube of insulation from which the mandrel has been stripped moves from the stripping station to the discharge station, cutters 234 trim the ends of the insulation.

From the foregoing it will be appreciated that as uid is supplied to the cylinders 288 of the assemblies 284 and 206, chucks 212 move in opposite directions across the respective units 118 and 120 to grasp the ends of mandrels positioned for stripping by the respective units 120 and 118. As the piston rods 21) reach the limit of their extended position, chucks 212 are supplied with air under pressure in a manner to be described to cause them to grasp the mandrel ends. When the mandrel ends have been grasped, the flow of fluid to the cylinders 288 is reversed to cause the chucks to withdraw the mandrels from the tubes of insulation. When the rods 21) again reach their fully retracted positions, the air is exhausted from the chucks to cause the chucks to release the mandrels which have been stripped from the tubes of insulation.

We provide our machine with means for receiving the mandrels stripped from the tubes of insulation and for feeding these mandrels to return conveyors. Referring now to FIGURES 3 and 6 to 8, a drive motor 236 energized from any convenient source of electrical energ drives a pulley 238 which drives a V belt 248 to drive an adjustable pulley 242 carried by the input shaft of a reducer cone drive 244. The speed at which the input shaft of drive 244 is driven may be adjusted in a manner known to the art by a sheave speed selector 246. Similarly the speed may be adjusted by actuating a speed selector 248 associated with pulley 238 in a manner known to the art. A clutch 250 and brake 252 connect the output shaft of reducer 244 to the input shaft of a gear drive 254 which drives an output shaft 256 rotatably supported in suitable bearings 258, 260 and 262 in the machine frame. A gear 264 carried by shaft 256 for rotation with the shaft drives an idler gear 266 which drives a gear 278 carried by a shaft 272 rotatably mounted in bearings 274 and 276 supported by the machine frame. The shaft 272 associated with unit 118 carries for rotation with it adjacent its respective ends a pair of arms 278 and 280. We mount arms 278 and 280 on shaft 272 at the midpoints along their lengths and form the ends of the arms with mandrel and receiving notches or slots 282. The shaft 256 which extends across the machine through unit 120 carries the pair of arms 278 and 280 associated with unit 120. From the foregoing description it will readily be apparent that the arms 278 and 280 adjacent the unit 118 carry away mandrels which have been stripped from the unit 120 while the arms 278 and 280 adjacent unit 120 carry away stripped mandrels which come from unit 118.

Referring now to FIGURE 6, a sprocket wheel 284 carried by shaft 276 intermediate the units 118 and 120 for rotation with the shaft drives a pitch chain 286 which engages and drives a sprocket wheel 288 carried by a shaft 290 for rotation with the shaft. Any convenient means such as a bearing or the like rotatably supports shaft 290 in a bracket 292 carried by the machine frame.

A pivot shaft 294 supported in bracket 292 rotatably carries a pair of arms 296, each one of which is associated with a respective unit of the machine. Springs 298 extending between the arms 296 and the bracket 292 normally urge the arms to positions at which cam followers 388 carried by the arms are in engagement with the surfaces of respective cams 302 secured to shaft 298 by keys 384. The diameter of sprocket wheel 288 is approximately half the diameter of wheel 284 with the result that shaft 2.9i) makes two revolutions for each revolution of shaft 272.

When the air supply to the stripper cylinder is reversed in a manner to be described, the solenoids of the clutch and brake 258 and 252 are energized to couple the output shaft of drive shaft 244 to the input shaft of drive 254 to cause shafts 256 and 272 to be driven. As the mandrel is withdrawn from the tube of insulation, the fingers 296 associated with each unit 118 and 120 are moved upwardly to the broken-line position shown in FIGURE 6 to support the mandrel shaft ends remote from the chucks when the mandrels have been completely withdrawn from the tubes of insulation. At the time the air supply to the chucks is exhausted to release the mandrel ends gripped by the chucks and as the pistons associated with the stripper cylinders arrive at their completely withdrawn positions, arms 278 and 280 associated with each unit pick the mandrel ends up from the chucks and from the fingers 296. It is to be understood as will be explained hereinafter, that in the course of each unloading operation shafts 256 and 272 rotate through a half revolution. At the end of an unloading operation each pair of arms supports a stripped mandrel in the slots 282 located at corresponding arm ends. The other slots are positioned to pick up a mandrel during the next unloading operation. Between successive movements of the arms 278 and 280 the empty mandrels carried by the slots 282 in one end of the arms of each pair are picked out of the slots by carriers 306 fixed on the chains of mandrel return conveyors indicated generally by the reference characters 308 and 310. The return conveyors 308 and 310 return the stripped mandrels to the winding machine (not shown) with which our mandrel stripper is associated.

Referring now to FIGURE 7, the drive shaft 138 of our stripper carries for rotation with the shaft a cam 312 adapted to actuate a slider 314 slidably carried in the machine frame. Slider 314 engages a lever 316 pivotally carried by a shaft 318 on the machine frame. The end of lever 3:16 remote from slider 314 drives a link 328 adapted to actuate a switch 322. Each half revolution of shaft 136` cam 312 actuates lever 316 to close switch 322.

Referring now to FIGURE ll, one form of control circuit which may be used with our mandrel stripper includes respective conductors 324 and 326 connected to the terminals 328 and 338 of a suitable source (not shown) of electrical energy. We connect the solenoid windings 332 and 334 associated with the respective clutch and brake 132 and 134 in parallel with each other in series with a normally closed switch 1R-J; and a normally closed stop switch 336 between conductors 324 and 326. With this series circuit complete, the clutch and brake solenoid windings 332 and 334 are energized to couple shaft i136 to shaft 130 to cause arms y142 and 144 to rotate. When, from a starting point at which 1R1 is closed, shaft has been driven to position the pairs of strippers 146` and 154, for example, at the stripping station at which they hold a wrapped mandrel in a position to be stripped and to position the pairs of strippers 148 and 156, for example, at the delivery station at which they deliver a stripped tube of insulation, cam 312 pivots lever 316 through the medium of slider 314 to close switch 322, indicated schematically in FIGURE ll as 1LS. We connect switch yILS in series with a relay winding l1R. When switch ILS closes in the manner described, relay winding 1R is energized to open switch 1R41 to de-energize windings 332 and 334 to uncouple shaft `131? from shaft `136 and to stop the shaft 130.

Energization of winding 1R also closes a normally open switch 1R42 connected in series with a valve solenoid winding S41 and a normally closed switch 2R-'1. Winding S-I is associated with a valve, indicated generally by the reference `character 3318 adapted in one condition to supply air to the stripper cylinders S in a direction to cause the associated rods 210 to move the chucks 212 inwardly of the machine and in the other condition to supply air lto the cylinders to move the chucks 212 outwardly of the machine. In the arrangement shown with winding S-1 de-energized valve 338 supplies fluid to the cylinders in a direction to cause them `to retract the chucks 21.2. When switch IR-2 closes in the manner described hereinabove, Iwinding S-1 is energized to operate valve 333 to supply air to the cylinders to move the chucks '212 into the machine.

Energization of winding 1R also closes a normally open switch 1R43 connected in series with an oven unloader valve winding S3 and a normally closed switch 2R42. Winding S-3 is associated with a valve, indicated generally -by the reference character 340 adapted in one condition to supply fluid under pressure to cylinder 52 to move rod Sii upwardly as viewed in FIGURE 9 and in the other condition to supply fluid to cylinder 52 in a direction to move rod 50 downwardly as Viewed in FIG- URE 9. With winding S-Zt de-energized, valve 340 supplies fluid to cylinder 52 in a direction to move rod 50 downwardly as viewed in FiGURE 9. When switch yIR-3 closes in the manner described winding S-3 is energized to actuate valve 340 to move rod 50i upwardly as viewed in lFlGURE 9 to cause arms `34 and 36 to rotate in a clockwise direction toward an open mold of the oven 1t). It is to be understood that the oven drive must be coordinated with the action of cylinder 52 to ensure that a mold towards which arms 34 and 36 move is open.

As the chucks 212 reach the limits of their travel inwardly of the machine one of them momentarily actuates a limit switch ZLS connected in series with a relay winding '2R between conductors 324 and 326i. This actuation of limit switch 2LS energizes winding 2R to close a normally open switch `2R43 connected in series between the terminal of winding 2R to lwhich switch I2L-S is connected and one terminal of a normally closed switch .3R-2, the other terminal of which is connected to conductor 324 to complete a holding circuit for winding 2R. The energization of winding 2R closes a normally open switch 2id-4 connected in series with a normally closed switch 3R-3 and with chuck valve winding S-2 between conductors 324 and 326. Winding S-Z is associated with a valve indicated generally by the reference character 342 adapted in one condition to supply air under pressure to chucks 212 to cause the lchucks to grasp mandrel ends and in the other condition to exhaust the air from the chucks. yIn the arrangement shown with winding S-Z deenergized, valve 342 is in a condition at which the air 1s exhausted from the chucks. When switch 2R-4 closes, winding S-2 is energized to actuate valve 342 to supply fluid under pressure to the chucks to cause the chuck jaws to close on a mandrel end. It -will be `remembered that at this time the chucks 212 are at the l1m1t of the1r movement inwardly of the machine.

Energization of winding 2R also opens swltch 2R-2 to de-energize solenoid S-3 to permit valve 34@ to reverse the flow of uid to the oven unloader cylinder 52 to withdraw arms 34 and 36 from the open mold to remove a wrapped mandrel from the mold.

After a slight delay to ensure that the mandrel ends are rmly gripped by the chucks, switch 2R-1 opens to de-energize winding S-1 to permit valve 338 to reverse the flow of ilu-id to the cylinders 208 to cause the chucks to move outwardly of the machine tostrip the mandrels from the tubes of insulation carried by the closed pairs of grippers 146 and 14S.

We connect a normally open switch ZR-S associated with winding 2R in series with the parallel connected clutch and brake solenoid windings 344 and 346 associated with the clutch and brake 250 and 252 between conductors 324 and 326. Energization of winding 2R closes switch 2R-5 to energize windings 344 and 345 to cause shafts 256 and 272 to be driven to operate the unloader mechanism of our stripper.

When the chucks 212 approach their fully retracted position, they momentarily close a normally open switch 3L-S connected in series with a relay winding 3R between conductors 324 and 326. Energization of winding 3R in this manner causes switch 3R-3 to open and thus to deenergize winding S-2 to permit valve 342 to exhaust the air from the chucks to release the mandrel ends. As the chucks release the mandrel ends the pair of arms 278 and 280 associated with each unit have moved to a position at which they pick up the stripped mandrel from the chucks and from fingers 296. Energization of winding 3R closes switch 3R-1 to complete the circuit of clutch and brake windings 332 and 334 through a selector switch arm 34S in engagement with a contact 350 providing automatic operation. As shaft begins to turn, cam 312 permits switch 1LS to open to de-energize winding 1R t0 complete the circuit of windings 332 and 334 through switch 1R-1 and to open switches 1R-2 and 1R-3.

Energization of winding 3R also opens switch 3R-2 after a short delay to permit the stripped mandrel removal arms to reach a position at which the removal conveyor can receive the mandrel. The delayed action of switch 3R-2 may be provided by any suitable means such as by a dashpot 339. Opening of switch 3R-2 interrupts the holding circuit of winding 2R to de-energize this winding and permit switch 2R-5 to open to de-energize the windings 344 and 346 of the uploader drive clutch and brake. We so arrange our system that switch 3R-2 does not open until after winding 1R is de-energized to open switches 1R-2 and 1R-3 so that windings S-l and S-2 will not be energized by the closing of switches 2R-1 and 2R-4. It will be remembered that the stripped mandrels are now clear of the grippers so that they do not interfere with movement of the grippers.

In the operation of our control circuit described above the cycles of operation of the machine follow each other automatically. If it is desired to operate the machine manually, arm 348 may be moved to engage a contact 352 connected in series with a push-button switch 354 which is connected to the terminal of windings 332 and 334 to which switch 1R-1 is connected. In this manner the shaft 130 may be moved from the position at which cam 312 closes switch ILS and will complete a half revolution but will not automatically recycle at the end of the stripping and unloading operations. It is to be understood that the spacing of the carriers on chains 7S and Si) and of the carriers on the return conveyors 30S and 310 is such that the operation of these conveyors is synchronized with the operation of the remainder of the parts of the machine.

In operation of our mandrel stripper for mat winding machines assuming the parts are in the positions occupied just after a stripping operation has been completed, windings 332 and 334 are energized to cause shaft 130 to rotate through a half revolution. As the arms 142 and 144 move in a clockwise direction, as viewed in FIGURE 3, a tube of insulation from which a mandrel has been stripped has its ends trimmed by cutters 234. As the grippers 146 and 154 carrying tubes of insulation approach the delivery location, they are actuated to the open position to permit the trimmed tube from which the mandrel has been stripped to fall to be guided to the discharge conveyor 20) by the guide 202. At the same time in the course of a half revolution of shaft 134B, the grippers 148 and 156 which initially were open pick up a wrapped mandrel 32 from the conveyor including chains '78 and 80 and carry the mandrel to the location at which the stripping operation takes place. At the end of this half revolution of shaft 130 one pair of grippers such, for example, as the initially empty grippers 148 and 156 occupy the position shown in FIGURE 3 for the grippers 145 and 154i. At the same time, the gripper-s 146 and 154 have moved to a position to pick up a fresh mandrel on the next stepping operation of shaft 130. At the end of this half revolution of shaft 136, cam 312 actuates switch tLS to energize winding 1R to open switch 1R-1 to stop drive shaft 13) and to close switches 1R-2 and 1li-3 respectively to energize windings S-l and S-S to supply air to cylinders 298 to drive chucks 212 inwardly of the machine and to supply air to the cylinders 52 to move arms 34 and 36 to remove a wrapped mandrel from an open oven mold. In this latter operation as arms 34 and 3e move into the mold, latches 62 are cammed over the mandrel shaft ends 34. When winding S-3 is de-energized in a manner to be described, the latches 62 pull the mandrel out of the open mold mid as arms 34 and 36 rotate in a counterclockwise direction, as viewed in FIGURE 9, the latches are cammed by blocks 90 to release the mandrel ends to permit them to come to rest on carriers 84 on chains 73 and 80.

When, under the action of uid supplied through valve 338 the chucks 212 approach the limit of their inward movement, one of the chucks actuates a limit switch ZLS to energize winding 2R to open the circuit of winding S3 to permit the return action of arms 34 and 36 described above. At the same time, switch 2li-4 closes to complete the circuit of winding S-2 to supply air under pressure to the chucks through valve 342 to cause the chuck jaws to close on the mandrel ends. A short time after switch 2R4 closes, switch 2R-1 opens to reverse the ow of fluid to cylinders 263 through valve 338 to initiate the withdrawing action of chucks 212. The delayed action of switch ZR-l may be provided by any suitable means known to the art such as by a dashpot 337. As this takes place, switch ZPL-5 closes to energize windings 344 and 346 to cause shafts 256 and 272 to rotate. As these arms rotate and at the time the mandrels are fully stripped from the tubes of insulation, fingers 296 are moved by cams 302 to the broken-line position shown in FIGURE 6 to receive the inboard ends of the mandrels. As the chucks completely withdraw the mandrels and approach their outboard limit positions, one of the chucks momentarily actuates a switch SLS to complete the circuit of a winding 3R to exhaust the air supplied to chucks 212 through valve 342 and to re-energize windings 332 and 334 to cause shaft 130 to rotate. Shortly thereafter, switch 3R-2 opens and after switch 3R-3 opens, arms 278 and 2S() have moved from the position at which they pick the stripped mandrel from fingers 296 and from the chuck to the position at which they support the mandrel for removal by the return conveyors 308 and 316. The machine then recycles as before.

As is pointed out hereinabove, our machine includes two conveyors such as the conveyor 76 which receive wrapped mandrels 32 from two ovens. These conveyors carry the wrapped mandrels to the mandrel stripper illustrated in FIGURE 3 having two sets of axially displaced arms which are operated out of synchronism as are the conveyors to receive wrapped mandrels from the respective conveyors and to position them for operationy of the stripping units 264 and 2%. These stripping units likewise are operated out of synchronism so that the unit 206 strips a wrapped mandrel carried by the unit 118 and the stripper unit 264 strips a mandrel positioned between unit 120. These stripper units have associated therewith the stripped mandrel removal mechanism illustrated in FIG- URE 6 which has two sections respectively associated with the two stripper units 2% and 2%. As the stripper units operate the arms 278 and 2S@ carry the stripped mandrels to the return conveyors 3tlg and 319.

It will be seen that we have accomplished the objects of our invention. We have provided a mandrel stripper for mat winding machines which automatically removes wrapped mandrels from a curing oven, which strips the mandrels from the tubes of insulation, which trims the ends of thc stripped tubes and which automatically returns the stripped mandrels to return conveyors. Our stripper permits advantage to be taken of the potential productive capacity of winding and curing machines of the prior art. It permits the formation of finished tubes of insulation from a mat impregnated with uncured resin to the finished product. It greatly reduces the labor and expense involved in forming insulating tubes or ducts.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of our claims. It is further obvious that various changes may be made in details within the scope of our claims without departing from the spirit of our invention. It is, therefore, to be understood that our invention is not to be limited to the specific details shown and described.

Having thus described our invention, what we claim is:

l. A mandrel stripper for use with an oven for curing tubes of insulating material carried by elongated mandrels having ends including in combination, means for engaging said mandrel ends to remove mandrels carrying tubes of insulation from said oven, means for gripping tubes of insulation carried by mandrels and for carrying said tubes to a stripping station, means for receiving mandrel ends from said mandrel removing means and for moving said mandrels and tubes of insulation to a position which said tube gripping means can act on said tubes and means at said stripping station for grasping the end of a mandrel and for pulling said mandrel out of the tube carried thereby while said tube is retained by said gripping means.

2. A mandrel stripper as in claim l in which said tube receiving and moving means is adapted to deliver stripped tubes at a delivery station.

3. In an installation for forming nished tubes of insulation from mats of material wrapped on mandrels having ends, apparatus for removing wrapped mandrels from a curing oven having molds and for delivering said mandrels to a conveyor including a pair of arms, means for rotatably supporting said arms in spaced relationship adjacent said oven, means carried by said arms for receiving the respective ends of a mandrel, respective means carried by said arms and actuated in response to engagement with the respective ends of a mandrel for retaining said mandrel ends in said receiving means, said receiving and retaining means substantially surrounding said mandrel ends upon actuation of said retaining means to prevent movement of said mandrel ends out of said receiving means, said mandrel end retaining means comprising latches carried by said arms and means biasing said latches to ride over said mandrel ends as said arms move toward said mold and including means positioned adjacent said conveyor to move said latches against the action of said biasing means to permit said arms to deposit said mandrel on said conveyor and means for moving said arms toward an open mold to permit said arm-carried means to engage the ends of a mandrel and for moving said arms away from said mold to remove a mandrel the ends of which are engaged from said mold to deposit a removed mandrel on said conveyor.

4. In an installation for forming finished tubes of insulation from mats of material wrapped on mandrels having ends, apparatus for removing wrapped mandrels from a curing oven having molds and for delivering said mandrel to a conveyor including a pair of arms, means for rotatably supporting said arms in spaced relationship adjacent said oven, means carried by said arms for receiving the respective ends of a mandrel, respective means carried by said arms and actuated in response to engagement with the respective ends of a mandrel for retaining said mandrel ends in said receiving means, said receiving and retaining means substantially surrounding said mandrel ends upon actuation of said retaining means to prevent movement of said mandrel ends out of said receiving means, said mandrel arm receiving means comprising respective means forming recesses adapted to support the end of a mandrel, said mandrel end retaining means comprising respective latches pivotally carried by said arms and means for biasing said latches to ride over the ends of a mandrel as said arms move toward said mold, said apparatus including means positioned adjacent said conveyor for moving said latches against the action of said biasing means as said arms move away from said mold to permit said arms to deposit said mandrel on said conveyor and means for moving said arms toward an open mold to permit said arm-carried means to engage the ends of a mandrel and for moving said arms away from said mold to remove a mandrel the ends of which are engaged from said mold to deposit a removed mandrel on said conveyor.

5. Apparatus for use with an oven for curing tubes of insulating material carried by mandrels having ends including in combination a pair of arms, means for rotatably supporting said arms in spaced relationship adjacent said oven, means carried by said arms for engagaing the respective ends of a mandrel, a conveyor for supporting mandrels by their ends, said conveyor having one end adjacent said oven and another end remote from said oven, means for moving said arms toward an open mold to permit said arm carried means to engage the ends of a mandrel and for moving said arms away from said mold to remove a mandrel the ends of which are engaged from said mold and to deposit a removed mandrel on said conveyor, means for driving said conveyor to move said mandrel toward said other conveyor end, gripping means comprising a pair of grippers and means adapted to be actuated to move said grippers toward and away from each other, means mounting said gripping means adjacent said other conveyor end for movement between a first position at which said grippers engage a tube of insuiatiny material carried by a mandrel from said conveyor end and a second position remote from said first position, means for moving said gripping means from said rst position to said second position, means responsive to movement of said gripping means from said first position to said second position for actuating said grippers to grip a tube of insulation carried by a mandrel received at said other conveyor end, a chuck adapted to be actuated to grasp a mandrel end, means mounting said chuck for movement toward and away from a tube of insulation carried by said gripping means at said second position, means for actuating said chuck and means for synchronizing said arm moving means and said conveyor drive means and said gripping means moving means and said chuck actuating means.

References Cited in the file of this patent UNITED STATES PATENTS 1,626,410 Halstead Apr. 26, 1927 1,817,099 Reed Aug. 4, 1931 2,349,456 Olson May 23, 1944 2,357,358 Read Sept. 5, 1944 2,521,991 Nelson Sept. 12, 1950 2,609,776 Sahlin Sept. 9, 1952 2,653,502 Meyer Sept. 29, 1953 2,681,723 McCabe June 22, 1954 2,802,586 Wingard Aug. 13, 1957 2,885,063 Austin et al May 5, 1959 2,910,192 Wells Oct. 27, 1959 

1. A MANDREL STRIPPER FOR USE WITH AN OVEN FOR CURING TUBES OF INSULATING MATERIAL CARRIED BY ELONGATED MANDRELS HAVING ENDS INCLUDING IN COMBINATION, MEANS FOR ENGAGING SAID MANDREL ENDS TO REMOVE MANDRELS CARRYING TUBES OF INSULATION FROM SAID OVEN, MEANS FOR GRIPPING TUBES OF INSULATION CARRIED BY MANDRELS AND FOR CARRYING SAID TUBES TO A STRIPPING STATION, MEANS FOR RECEIVING MANDREL ENDS FROM SAID MANDREL REMOVING MEANS AND FOR MOVING SAID MANDRELS AND TUBES OF INSULATION TO A POSITION WHICH SAID TUBE GRIPPING MEANS CAN ACT ON SAID TUBES AND MEANS AT SAID STRIPPING STATION FOR GRASPING THE END OF A MANDREL AND FOR PULLING SAID MANDREL OUT OF THE TUBE CARRIED THEREBY WHILE SAID TUBE IS RETAINED BY SAID GRIPPING MEANS. 